Liquid heater



Feb. 14, 1933. 1,897,758

LIQUID HEATER Filed May 7, 1930 3 Sheets-Sheet l lltlVENTOR M'cvlaa E176219)" BY 42 WW 7% ATTORNEYS Feb. 14, 1933. H L 1,897,758

LIQUID HEATER Filed May 7, 1930 3 Sheets-Sheet 3 INVENTOF M'wlaz' 15.[filler BY pmzwww ATTORN EYS Patented Feb. 14, 1933 UNITED STATES NICOLAI H. KILLER, OF CARBONDALE, PENNSYLVANIA LIQUID Application filedmay 7,

This invention relates to a heat trans ferring unit, and moreparticularly to a furnace which is adapted to heat such liquids aswater, oil and the like.

The present invention is particularly adapted to heaters used in the artof refining or cracking, and provides a furnace therefor having a newand improved arrangement of oil tubes whereby the transition of the hotcombustion gases from the radiant section of the oil tubes to theconvection section is accompanied with material defiections in the pathof said gases.

The invention also provides a novel 1mproved furnace constructionwhereby the hot gases of combustion are made to lead a circuitous pathbetween the tubes without the necessity of baflies.

The invention still further provides means for so arranging the radianttubes so as to render them easily accessible for cleaning orreplacement. These radiant tubes, .it should be noted are subjected tothe greatest amount of heat, and are the ones most susceptible to heatinjuries and the like.

The invention still further provides a novel furnace construction fordispersing the flame in the furnace so that the oil tubes may absorb themaximum heat from the fiame itself.

The invention also contemplates means for progressively constricting thepassage of the combustion gases as they pass in contact with the heatedtubes, so that the 0001 ..ing of these gases and the consequent decreaseof their volume will be counter-balanced suiiiciently to effectsubstantial constancy in the velocity of these gases.

The invention further contemplates means for preheating the air leadinginto the combustion chamber of the furnace by contacting this air withthe flue pipes of the system.

The invention also consists in certain new and important features ofconstruction and combinations of parts hereinafter set forth andclaimed.

Although the novel features which are believed to be characteristic ofthis invention will be particularly pointed out in the appended claims,the invention itself, as to HEATER 1930. Serial No. 450,411.

its objects and advantages, the mode of its operation'and the manner ofits organization ma be better understood by referring to the ollowindescription taken in connection with t e accompanying drawings forming apart thereof.

Fig. 1 shows a vertical longitudinal section through a furnace embodyingthe present invention.

Figs. 2, 3, 4, and 5 are transverse sections taken on line 2-2, 33, 44and 55 respectively, of Fig. 1, and

Fig. 6 is a front elevation of a furnace having parts broken away.

Like reference characters denote like parts in the several figures ofthe drawings.

In the following description and in the claims, tparts will beidentified by specificnames or convenience, but they are intended to beas generic in their application to similar parts as the art will permit.

In the specific exemplification of the pres- Y ent invention shown inthe accompanying drawings, asuitable frame structure 10 is provided uponwhich is built the setting of the furnace. This furnace is provided witha combustion chamber 11 having side walls 12 preferably inclined atangles of about 45 and connected at the bottom by a floor 13. Extendingthrough the floor 13 are a plurality of suitable burners 14, thecombustion supporting air for which is supplied by an air tunnel 15.

Extending along each 'sideof the combustion chamber 11, and convergingupwardly at a preferable angle of 60 with'the horizontal is a pair ofrows of radiant tubes 16 arranged in stagger relationship andconstituting the radiant heating sections of the furnace. These tubes 16derive a great deal of their heat by radiation from the flame of theburners 14, and if desired the furnace walls may be constructed ofrefractory brick-work which may be heated to incandescence to increasethis radiant factor.

The ends of the tubes 16 extend beyond the furnace walls and are joinedby suitable bends 17 and 18 or the like so as to rovide av seriesconnected between the individual tubes of the radiant section. The bends17 may be protected against heat losses by refractory material such ascinders 18 or by a plurality of removably mounted juxtaposed tiles. Byextending the ends of the tubes 16 beyond the furnace walls, these bendsare rendered easily accessible so that they may be removed for cleaningor replacement of the tubes.

Horizontally extending on the outer sides of these radiant tubes 16 area plurality of tubes 20 constituting the convection sections of thefluid circulating system. These tubes are confined in a convectionchamber 21, the walls of which are formed to effect a constriction inthe passage of combustion gases as they pass through the tubes, so thatirrespective of the cooling of these gases and the consequent decreasein volume thereof, their velocities will be maintained substantiallyconstant. All of these convection tubes 20 are connected in series byreturn bends, and they are also connected in series with the radianttubes 16 so that the oil is led into the lowest convection section ofthe tubes 20 and passed out through the last of the series of radianttubes 16. The furnace may be built and the radiant tubes 16 so inclinedthat all of the tubes 16 and 20 are of the same length thereby obviatingthe necessity of carrying more than one length tube in stock.

Extending along each side of the furnace setting is an air conduit 22,the top and bottom of which are provided with crown plates 23 and 24:.These plates 23 and 24 have passing therethrough flue pipes 25 leadinginto a conduit 26, the back end of which is connected to a chimney stack27 by flues 26. The fiue pipes 25 permit the flue gases from the chamber21 to pass therethrough and into the conduit 26, where they are passedout through the flues 26 and the chimney stack 27.

The back portion of each air conduit 22 is open to the atmospherethrough a flared portion 28 which is provided with a fan 29, or theremay be one fan with a bifurcated duct connected to each of the fluepipes 25. The front portion of each air conduit 22 is connected to aconduit 30 which is disposed along the front portion of the furnace andwhich lead to a conduit 31 connected to the air tunnel 15.

Itshould be noted that the heater is divided into two similar parts sothat two separate primary flows of oil through the two sides may beprovided at the same time. If desired, however, a single primary flow ofoil might be split into two paths through the two sides of the heaterand joined toether again after passing through the eater.

. The burner 14 should preferably be of the type which produces afantail shaped flame so that said flame substantially conforms with theshape of the furnace. This permits the absorption by the radiant tubes16 of a material amount of heat from the flame itself. However,regardless of the type of burner used, it is obvious that the inclinedside walls 12 aid in the dispersion of flames towards the radiant tubeseffecting thereby a corresponding increase in the transfer of heat fromthe flame itself.

Although oil burners are a suitable means for effecting combustion, itis obvious that the present invention is adapted to any type of fuel.Either gas, oil or coal dust may be burned in suitably designed burnerswith the necessary changes in furnace design.

Instead of dividing the heater into two main heating sections, i. e.,radiant and convection sections, it may be desirable in accordance withthe temperature of the incoming fluid to be heated to divide the heaterinto three main heating sections, constituted by a low rate or secondarysection, a primary or high rate convection section and a radiantsection. Under these conditions, the oil would first go through the lowrate convection section, then into the high rate convection section andfinally through the radiant section. This high rate convection sectionmay consist of another series of inclined tubes disposed behind theradiant tubes 16 in stagger relationship therewith. These highconvection tubes would then receive heat by radiation as well as bycontact with the very hot combustion gases.

In certain refining processes, the incoming flow of oil in the heaterwould be at such a temperature that it might be desirable to omit thehigh rate of convection sections.

It should be noted that the oil tubes are so arranged and the furnace soconstructed as to obviate the necessity of bafiies. Also by crossing thepath of the hot gases, by transversely disposed tubes 19, after theirpassage through the radiant tubes 16, this path is caused to be brokenup into a more circuitous route, thereby effecting a more intimatecontact between the hot gases and the convection tubes.

Although the invention has been described with particular adaptation tothe art of oil refining or cracking, it is obvious that it can be usedin any heat transfer unit such as a superheater, boiler or the likewithout departing from the spirit of the invention.

While certain novel features of the invention have been shown anddescribed and are pointed out in the annexed claims, it will beunderstood that various omissions, substitutions and changes in theforms and details of the device illustrated and in its operation may bemade by those skilled in the art without departing from the spirit ofthe invention.

I claim:

1. A heat transferring furnace including two series of oppositelydisposed inclined and upwardly converging sets of seriallyinterconnected tubes, and two series of serially interconnectedhorizontal tubes disposed at the outer sides of said first mentionedtubes and directly connected in series with said first mentioned tubes,all of said tubes being of substantially the same length.

2. A furnace for heating fluids, including a combustion chamber, a pairof convection chambers, each having a pair of walls converging in thedirection of the flow of the gases, so as to form a chambersubstantially triangular in vertical crosssection, and having an outletfor the gases of combustion at the apex thereof, whereby the velocity ofthe gases passing through said convection chambers will be maintainedsubstantially constant, a burner disposed in the lowermost portion ofsaid combustion chamber, said combustion chamber having side wallsdiverging upwardly from points closely adjacent to opposite sides ofsaid burner, said burner giving an upwardly extending flame having a fanshaped vertical cross-section, whereby the sides of said flame impingeson said side walls and is dispersed thereby, said flame beingunobstructed in a vertical direction,-'a first set of tubes comprisingtwo separate series of serially interconnected straight tubes, the twoseries 'of tubes converging upwardly, so as to gradually decrease thewidth of the combustion chamber towards the top, and serving to separatesaid combustion chamber fromv said convection chambers, a second set oftubes comprising two separate series of serially interconnected straighttubes of substantial equal length, extending transversely of the tubesof the first set in the rear thereof, and interconnected serially withthe corresponding adjacent series of said first set, andhaving the innerrow thereof extending substantially the full length of the tubes of thecorresponding series of tubes of said first set, said second set oftubes being disposed in said convection chambers, so that the convergingwalls of said chambers are disposed adjacent to said last mentionedtubes, whereby the gases will be in contact with said tubes, while underthe influence of the constriction of the convection chambers formed bysaid converging walls.

3. A furnace for heating fluids, including a combustion chamber having abottom wall, a burner in said bottom wall, said combustion chamberhaving side walls diverging upwardly from points adjacent to oppositesides of said burner, a first set of tubes comprising two separateseries of straight tubes extending longitudinallyupward, and covergingtowards the top of the combustion chamber from points adjacent will bein contact with said tubes while un-' der the influence of theconstriction of the convection chambers caused by said converging walls,the tubes of the first and second series of each set being seriallyconnected.

4. A furnace for heating fluids, including a combustion chamber, asource of heat in said combustion chamber, a first set of seriallyinterconnected tubes extending substantially towards the top of saidchamber, and bounding at least a portion of the sidesof said combustionchamber, a convection chamber progressively constricted in the directionof flow of said gases from the ends of the tubes of said first series oftubes, :1 second set of serially interconnected straight tubes disposedin said convection chamber so that the gases of combustionwill be incontact with said tubes while under the influence of the constriction ofsaid convection chamber, said second set of tubes being transverselydisposed with respect to said first set of tubes, and directly connectedserially thereto, said second set of tubes having the row thereof whichis disposed adjacent to said first set of tubes extending substantiallythe full length of said first set of tubes.

5. A heat transfer furnace including a combustion chamber, a convectionchamber having converging side walls to gradually decrease the area forgas flow therethrough, the larger end of said convection chamber beingin open communication with said combustion chamber, a first set ofserially interconnected straight tubes disposed across the inlet to theconvection chamber from. said combustion chamber, and a second set ofserially interconnected straight tubes disposed in said convectionchamber in the rear of said first set of tubes and adjacent thereto, thetwo sets of tubes being disposed transversely with respect to each otherand connected in series, all of the tubes of both sets being ofsubstantially the same length.

6. A heat transfer furnace including a combustion chamber, a convectionchamber having converging side Walls to gradually decrease the area forgas flow thercthrough,

the larger end of said convection chamber being in open communicationwith said combustion chamber, a first set of serially interconnectedstraight tubes disposed across the inlet to the convection chamber. fromsaid combustion chamber, and a second set of serially interconnectedstraight tubes disposed in said convection chamber in the rear of saidfirst set of tubes and adjacent thereto, and including a plurality ofrows of tubes, said rows having gradually decreasing numbers of tubes inthe direction of gas flow, the two sets of tubes being disposedtransversely with respect to each other and connected in series, all ofthe tubes of both sets being of substantially the same length.

7 A heat transfer furnace including two series of oppositely disposed,inclined, and upwardly converging sets of tubes, two series ofhorizontally disposed tubes at the outer sides of said first mentionedtubes, all of said tubes being of substantially the same length, andremovable means connecting the tubes of each set in series andconnecting the sets in series, whereby any tube may be removedindependently of the others, and all of the tubes of both sets areinterchangeable.

8. A heat transfer furnace including a combustion chamber, a convectionchamber having side walls converging in the direction away from saidcombustion chamber to gradually decrease the area for gas flowtherethrough, a first set of straight tubes disposed across the inlet tosaid convection chamber at the wider end thereof, a second set ofstraight tubes disposed in the rear of said first set of tubes and insaid convection chamber, all of the tubes of both sets being ofsubstantially the same length, and detachable means connecting the tubesof each set in series and connecting said sets in series, whereby anytube may be removed independently of the others and replaced by a tubeof predetermined length.

9. A furnace for heating liquids including a combustion chamber havlng abottom wall provided with a burner and side walls extending upwardlyfrom said bottom wall and diverging from adjacent to said burner, a pairof convection chambers opening into said combustion chamber on oppositesides thereof and above said side walls, each of said convectionchambers being substantially triangular in vertical cross-section andincluding a pair of walls converging in the direction of flow of gasesfrom said combustion chamber and having an outlet at the apex thereoffor the gases of combustion, and a set of serially connected,substantially horizontal tubes disposed in each of said convectionchambers, the rows of tubes of said sets nearest to said combustionchamber being disposed in planes that converge upwardly from adjacent tothe upper edges of said side walls toward the upper end of saidcombustion chamber.

10. A furnace for heating liquids including a combustion chamber havinga bottom wall provided with a burner and side walls extending upwardlyfrom said bottom wall and diverging from adjacent to said burner, a pairof convection chambers opening into sald combustion chamber on oppositesides thereof and above said side walls, each of said convectionchambers being substantially triangular in vertical cross-section andincluding a pair of Walls converging in the direction of flow of gasesfrom said combustion chamber and having an outlet at the apex thereoffor the gases of combustion, and a set of substantially horizontal tubesall of substantially the same length and disposed in each of saidconvection chambers said tubes being arranged in a plurality ofsubstantially parallel rows, the rows of tubes of said sets nearest tosaid combustion chamber being disposed in planes that converge upwardlyfrom adjacent to the upper edges of said side walls toward the upper endof said combustion chamber, and the tubes of the several rows beingserially connected to provide counterflow in respect to the out flowingases. v

Signe at New York in the county of New York and State of New York, this5th day of May, A. D. 1930.

NICOLAI H. HILLER.

